Improvement in burglar-alarms



L. F. DRAKE.

BURGLAR-ALARM.

Patented N-ov.9,1875.

NITED STATES PATENT Qrrrce.

LEVI F. DRAKE, OF BROOKLYN, NEW YORK, ASSIGNOR OF ONE-HALF HIS RIGHT TO SAMUEL HUGHAN, OF SAME PLACE.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent No. 169,788, dated November 9,1875; application filed September 28, 1875.

To all whom it may concern:

Be it known that I, LEVI F. DRAKE, of

Brooklyn, in the county of Kings and State of New York, have invented an Improvement in Burglar-Alarms; and I do hereby declare that the following is a full, clear, and exact description of the same. I

My invention relates to a device which may be readily applied to a door or window of any description, for the purpose of giving notice of any attempt to effect an entrance thereby. The invention consists in a weight having a fulminate cartridge or torpedo attached, and in a certain construction of the weight and means for suspending it from the door or window or frame thereof, whereby the opening of the door or window will cause the weight to drop and the cartridge or topedo to explode.

In the accompanying drawing, Figure 1 is a perspective view of the interior of a room, with my improved burglar-alarm applied to the door. Fig.2 is a detail view of the weight and means for suspending it.

The weight B may be made of any suitable substance; but I prefer to make it of lead or other metal. It is of conical, pyramidal, or similar form, that one end may be heavier than the other. The base orlarger end of the weight may be flat or rounded, and has attached to it, by suitable adhesive material or otherwise, a fulminate cartridge or torpedo, O, of any suitable description which will explode .by percussion. At the upper or smaller end of the weight is an eye, I), for the attachment of a cord or thread, E. The weight, be-

ing of conical or pyramidal form, and thus having one end heavier than the other, when liberated from suspension at its smaller or lighter end, will maintain an upright position during its fall, and will strike the ground with its larger or heavier end, to which the torpedo is attached, and thereby effect the certain explosion of the torpedo.

In applying the apparatus to a door, a nail or a common pin, g, is driven into the jamb or frame G, near the hinged edge of the door, or in any other place where the weight may fall from it on a fair surface, and over this .nail or pin the cord or thread E is passed, so as to allow the weight B to hang vertically, as shown in Fig. 1. The free end of the thread is then inserted in the crack or crevice between the opposite edge of the door and the contiguous portion of the frame, and secured just tight enough to hold the weight suspended while the door remains closed, but allow the weight to drop as soon as the door is opened. Any suitable means may be employed for holding the thread in place; but I have shown in the drawing a Wedge, J, as a convenient means for the purpose, and as being adaptable to cracks or crevices of various widths andreadily inserted in place.

The apparatus being adjusted in the' manner shown in full lines in Fig, 1, when the door is opened the wedge J will drop to the floor and release the cord or thread E. whereupon the weight B, being no longer restrained by the thread, will descend in a direct line and strike the floor with such force as to explode the cartridge or torpedo O. The force of the explosion will depend on the character of the compound used in making the cartridge. The position of the parts when the door is opened is indicated by dotted lines.

The invention may be applied to a window by inserting the cord and wedge between the sashes, or in any other position where they will be displaced by the opening of the window.

What I claim as new, and desire to secure by Letters Patent, is

A burglar-alarm consisting of a conical weight having a flat or rounded bottom, to which is attached on the outside, by means of adhesive material, a pellet of fulminate, and provided at its upper end with an eye, by which it may be secured to a string and fastened to a door or window in such position as to drop and fall, with the fulminate down, when the door or window is opened, and discharge the fulminate, substantially as described.

L. F. DRAKE.

Witnesses: I MIcHAEL RYAN, BENJAMIN W. HOFFMAN. 

